摘要
本文采用相干势近似(CPA)和Anderson-Newns(AN)模型研究了过渡金属原子在无序二元合金(DBA)表面上的化学吸附。普遍的去耦合方法被用来消除过渡金属吸附原子不同d电子之间通过与衬底表面相互作用所产生的耦合效应。对于DBA,考虑了表面偏析现象,尤其研究了因化学吸附而导致表面偏析的变化。计算结果表明:(1)过渡金属吸附原子对DBA表面偏析有很大的抑制作用;(2)化学吸附系统Pt/Ni_xCU_(1-x)随Ni原子体浓度的增加而趋于稳定。
The coherent-potential approximation(CPA) and the Anderson-Newns (AN) model are used to study a transition metal adatom chemisorption on surface of a disordered binary alloy(DBA). The general method for elimination of coupling generated from d-orbital electrons of a transition-metal adatom acted with the surface of substrate is adopted. For the DBA, the effect of surface segregation, especially the change of surface segregation due to chemisorption is investigated. The results are as follows: (1) A transition metal adatom constrains surface segregation. (2) For the system of Pt/Ni_xCu_(1-x), chemisorption energy △E decreases with the increase of Ni concentration Xb, resulting in a more stable chemisorption.
出处
《辽宁大学学报（自然科学版）》
CAS
1992年第3期54-60,共7页
Journal of Liaoning University：Natural Sciences Edition
关键词
无序二元合金
化学吸附
过渡金属
Coherent-Potential Approximation(CPA), I)isordered Binary Alloy(DBA), Chcmisorption.
